[Unit]
Description=lchat connect broker (OAuth relay + token exchange)
After=network-online.target
Wants=network-online.target

[Service]
# /data/connect.env holds LCHAT_ADMIN_TOKEN + the DNSimple OAuth client_id/secret
# + the registered redirect_uri. Required (no leading '-'): a misconfigured broker
# breaks connecting services fleet-wide, so it must fail to boot rather than start
# silently broken.
EnvironmentFile=/data/connect.env
ExecStart=/opt/lchat/connect --addr /run/lchat/connect.sock --db /data/connect.db
Restart=always
RestartSec=1

# --- hardening (see docs/instance-router.md § Hardening) ---
User=lchat
Group=lchat
CapabilityBoundingSet=
NoNewPrivileges=yes
ProtectSystem=strict
ProtectHome=yes
ReadWritePaths=/data /run/lchat
PrivateTmp=yes
PrivateDevices=yes
ProtectClock=yes
ProtectHostname=yes
ProtectKernelTunables=yes
ProtectKernelModules=yes
ProtectKernelLogs=yes
ProtectControlGroups=yes
ProtectProc=invisible
RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX
RestrictNamespaces=yes
RestrictRealtime=yes
RestrictSUIDSGID=yes
LockPersonality=yes
MemoryDenyWriteExecute=yes
SystemCallFilter=@system-service
SystemCallErrorNumber=EPERM
SystemCallArchitectures=native
MemoryMax=256M
TasksMax=256

[Install]
WantedBy=multi-user.target